Mine tailings to add value to the agricultur​al sector

Energy100fm

February 27, 2013 9:54 am

Author:

Nampa

Phosphates in mine tailings from the Okorusu Fluorspar Mine will in the near future be used as commercial fertiliser for crops in the maize triangle.
Mine tailing refer to materials left over after the extraction of valuable minerals from ore.
The project, which is in its pilot stage, is the result of a collaboration between the Namibian Agronomic Board (NAB) and the mine, which is situated between Otjiwarongo and Otavi.
NAB Chief Executive Officer (CEO) Christof Brock said in a media statement issued on Monday the idea took hold at a time when the price of phosphate fertilisers became highly inflated and a viable alternative was needed.
“The next step in the process is to step up production as a continuous process in a small-scale pilot laboratory housed in two containers with the aim of ensuring that it can be a commercially feasible operation in its own right. Calculating the feasibility of full scale production is envisaged to take place after the next six months,” she said.
The mining process at Okorusu contributes significantly to the success of this initial phase of the project because after blasting, the rock is ground quite finely, making laboratory work that much easier.
According to Brock, the alternative would be for the NAB to set up and operate a rock-crushing section that would immediately bring into question the financial viability of the project.
Extracting such a valuable product from the waste of mining activity in the area is not limited to the extraction of phosphates only, according to Brock.
A by-product of the laboratory process, almost by accident, is liquid calcium nitrate. Calcium nitrate is sought after in the horticulture industry, which contributes to the taste and improved shelf-life of produce such as potatoes, according to Brock.
In addition to the abundance of the phosphate compound in the mine tailings, the NAB CEO emphasised that the significant reduction in cost to farmers is an advantage since a significant cost of fertilisers comes from transportation from beyond the borders of Namibia.
This would be the first of its kind and a fully-fledged phosphate extraction plant in Namibia.
“The feasibility study of the project at full-scale production is set to be completed over the next year and should full-scale production prove to be viable, developing the phosphate production site could realise within three to four years,” added Brock.